KR20240048503A - Mehtod and appratus for pucch repetition transmission in wireless communication system - Google Patents

Abstract

A method of operating a terminal in a wireless communication system, comprising: receiving system information by the terminal; transmitting a random access preamble based on the system information; receiving a response to the random access preamble; and uplink included in the response. It may include performing uplink transmission scheduled based on a link grant, receiving a contention resolution message based on the uplink transmission, and repeatedly transmitting a PUCCH including a HARQ-ACK for the contention resolution message. there is.

Description

PUCCH repeat transmission method and apparatus in a wireless communication system {MEHTOD AND APPRATUS FOR PUCCH REPETITION TRANSMISSION IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a method and apparatus for performing physical uplink control channel (PUCCH) repetition transmission in a wireless communication system. The present invention relates to a method and apparatus for performing PUCCH repetitive transmission in non-terrestrial networks (NTN).

The International Telecommunication Union (ITU) is developing the International Mobile Telecommunication (IMT) framework and standards, and is currently discussing 5th generation (5G) communications through a program called “IMT for 2020 and beyond.” .

In order to meet the requirements presented by “IMT for 2020 and beyond,” the 3rd Generation Partnership Project (3GPP) NR (New Radio) system takes into account various scenarios, service requirements, potential system compatibility, etc., and provides time-frequency Discussions are underway to support various numerologies for resource unit standards.

In addition, the new communication system uses not only terrestrial networks (TN) but also non-terrestrial networks (NTN) to enable mobile terminals (e.g. vehicle/train/ship type terminals/personal smartphones). Discussions are underway on how to support uninterrupted communication services at the service level.

The present invention relates to a method and device for performing PUCCH repetitive transmission in an NTN environment.

The present invention can provide a method and device for performing PUCCH repetitive transmission for coverage enhancement in an NTN environment.

The present invention relates to a method and device for increasing coverage for voice and low-latency services in an NTN environment.

According to one embodiment, in a method of operating a terminal in a wireless communication system, the terminal receives system information, the terminal transmits a random access preamble based on the system information, and the terminal receives a response to the random access preamble. , performing uplink transmission scheduled based on the uplink grant included in the response, receiving a contention resolution message based on the uplink transmission, and repeatedly transmitting PUCCH including HARQ-ACK for the contention resolution message. It may include steps.

The features briefly summarized above with respect to the present disclosure are merely exemplary aspects of the detailed description of the present disclosure described below, and do not limit the scope of the present disclosure.

According to the present disclosure, a method of performing PUCCH repetitive transmission in an NTN environment can be provided.

According to the present disclosure, coverage can be increased through repeated PUCCH transmission in an NTN environment.

According to the present disclosure, low-delay services can be provided based on increased coverage in an NTN environment.

The present disclosure is not limited to the effects described above, and other effects not mentioned may be clearly understood by those skilled in the art from the description below.

1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied.
Figure 2 is a diagram showing an NR resource structure to which the present disclosure can be applied.
Figure 3 is a diagram showing an NTN including a transparent satellite to which the present disclosure can be applied.
FIG. 4 is a diagram illustrating an NTN including a regenerative satellite without inter-satellite links (ISL) to which the present disclosure can be applied.
Figure 5 is a diagram showing an NTN including a reproduction satellite with an ISL to which the present disclosure can be applied.
FIG. 6 is a diagram illustrating a user plane (UP) protocol stack structure in an NTN including a transparent satellite to which the present disclosure can be applied.
FIG. 7 is a diagram illustrating a control plane (CP) protocol stack structure in an NTN including a transparent satellite to which the present disclosure can be applied.
Figure 8 is a diagram showing a timing advance calculation method to which the present disclosure can be applied.
FIG. 9 is a diagram illustrating an earth fixed cell scenario to which the present disclosure can be applied.
FIG. 10 is a diagram illustrating an earth moving cell scenario to which the present disclosure can be applied.
FIG. 11 is a diagram illustrating a method of mapping PCI to satellite beams to which the present disclosure can be applied.
FIG. 12 is a diagram for explaining a random access procedure to which the present disclosure can be applied.
FIG. 13 is a diagram illustrating a method of indicating terminal capability information for PUCCH repetitive transmission to which the present disclosure can be applied.
FIG. 14 is a diagram illustrating a method for indicating the number of PUCCH repeated transmissions to which the present disclosure can be applied.
Figure 15 is a diagram showing a method of indicating NTN terminal capability information to which the present disclosure can be applied.
Figure 16 is a flowchart of a method for indicating the number of PUCCH repetitions to which the present disclosure can be applied.
Figure 17 is a flowchart showing a method of indicating NTN terminal capability information to which the present disclosure can be applied.
Figure 18 is a diagram showing a device configuration to which the present disclosure can be applied.

Hereinafter, with reference to the attached drawings, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily practice them. However, the present disclosure may be implemented in many different forms and is not limited to the embodiments described herein.

In describing embodiments of the present disclosure, if it is determined that detailed descriptions of known configurations or functions may obscure the gist of the present disclosure, detailed descriptions thereof will be omitted. In addition, in the drawings, parts that are not related to the description of the present disclosure are omitted, and similar parts are given similar reference numerals.

In the present disclosure, when a component is said to be “connected,” “coupled,” or “connected” to another component, this is not only a direct connection relationship, but also an indirect connection relationship in which another component exists in between. It may also be included. In addition, when a component is said to “include” or “have” another component, this does not mean excluding the other component, but may further include another component, unless specifically stated to the contrary. .

In the present disclosure, terms such as first and second are used only for the purpose of distinguishing one component from other components, and do not limit the order or importance of the components unless specifically mentioned. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, the second component in one embodiment may be referred to as a first component in another embodiment. It may also be called.

In the present disclosure, distinct components are intended to clearly explain each feature, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to form one hardware or software unit, or one component may be distributed to form a plurality of hardware or software units. Accordingly, even if not specifically mentioned, such integrated or distributed embodiments are also included in the scope of the present disclosure.

In the present disclosure, components described in various embodiments do not necessarily mean essential components, and some may be optional components. Accordingly, embodiments consisting of a subset of the elements described in one embodiment are also included in the scope of the present disclosure. Additionally, embodiments that include other components in addition to the components described in the various embodiments are also included in the scope of the present disclosure.

This disclosure describes a wireless communication network, and operations performed in the wireless communication network are performed in the process of controlling the network and transmitting or receiving signals in a system (e.g., a base station) in charge of the wireless communication network, or This can be done in the process of transmitting or receiving a signal from a terminal connected to a wireless network.

It is obvious that in a network comprised of a plurality of network nodes including a base station, various operations performed for communication with a terminal may be performed by the base station or other network nodes other than the base station. 'Base Station (BS)' can be replaced by terms such as fixed station, Node B, eNodeB (eNB), ng-eNB, gNodeB (gNB), and Access Point (AP). . In addition, 'terminal' can be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station), SS (Subscriber Station), and non-AP station (non-AP STA). You can.

In the present disclosure, transmitting or receiving a channel includes transmitting or receiving information or signals through the corresponding channel. For example, transmitting a control channel means transmitting control information or signals through the control channel. Similarly, transmitting a data channel means transmitting data information or signals through a data channel.

In the following description, the term NR (New Radio) system is used for the purpose of distinguishing the system to which various examples of the present disclosure are applied from existing systems, but the scope of the present disclosure is not limited by this term. .

The NR system supports a variety of subcarrier spacing (SCS) by considering various scenarios, service requirements, and potential system compatibility. In addition, the NR system uses multiple channels to overcome unfavorable channel environments such as high path-loss, phase-noise, and frequency offset that occur at high carrier frequencies. Can support transmission of physical signals/channels through beams. Through this, the NR system can support applications such as enhanced Mobile Broadband (eMBB), massive Machine Type Communications (mMTC)/ultra Machine Type Communications (uMTC), and Ultra Reliable and Low Latency Communications (URLLC).

Hereinafter, 5G mobile communication technology may be defined to include not only the NR system, but also the existing Long Term Evolution-Advanced (LTE-A) system and Long Term Evolution (LTE) system. 5G mobile communication may include technology that operates in consideration of backward compatibility with previous systems as well as the newly defined NR system. Therefore, the following 5G mobile communication may include technology operating based on the NR system and technology operating based on previous systems (e.g., LTE-A, LTE), and is not limited to a specific system.

First, I would like to briefly explain the physical resource structure of the NR system to which the present invention is applied.

1 is a diagram for explaining an NR frame structure to which the present disclosure can be applied.

일 수 있고,

이고, N=4096일 수 있다. 한편, LTE에서 시간 도메인 기본 단위는

일 수 있고,

이고,

=2048일 수 있다. NR 시간 기본 단위와 LTE 시간 기본 단위 사이의 배수 관계에 대한 상수는 k=

로서 정의될 수 있다.In NR, the basic unit of the time domain is

It can be,

, and N=4096. Meanwhile, in LTE, the basic unit of time domain is

It can be,

ego,

= could be 2048. The constant for the multiplier relationship between the NR time base unit and the LTE time base unit is k=

It can be defined as:

를 가질 수 있다. 여기서, 하나의 프레임은

시간에 해당하는 10개의 서브프레임으로 구성된다. 서브프레임마다 연속적인 OFDM 심볼의 수는

=

일 수 있다. 또한, 각 프레임은 동일한 크기의 2개의 하프 프레임(half frame)으로 나누어지며, 하프 프레임 1은 서브 프레임 0-4로 구성되고, 하프 프레임 2는 서브 프레임 5-9로 구성될 수 있다.Referring to Figure 1, the time structure of the frame for downlink/uplink (DL/UL) transmission is

You can have Here, one frame is

It consists of 10 subframes corresponding to time. The number of consecutive OFDM symbols per subframe is

=

It can be. Additionally, each frame is divided into two half frames of the same size, where half frame 1 may be composed of subframes 0-4, and half frame 2 may be composed of subframes 5-9.

는 하향링크(DL)와 상향링크(UL) 간의 타이밍 어드밴스(TA)를 나타낸다. 여기서, 상향링크 전송 프레임 i의 전송 타이밍은 단말에서 하향링크 수신 타이밍을 기반으로 아래의 수학식 1에 기초하여 결정된다.

represents the timing advance (TA) between downlink (DL) and uplink (UL). Here, the transmission timing of the uplink transmission frame i is determined based on Equation 1 below based on the downlink reception timing at the terminal.

[Equation 1]

은 듀플렉스 모드 (duplex mode) 차이 등으로 발생하는 TA 오프셋 (TA offset) 값일 수 있다. FDD (Frequency Division Duplex)에서

은 0 값을 가지지만, TDD (Time Division Duplex)에서는 DL-UL 스위칭 시간에 대한 마진을 고려해서

의 고정된 값으로 정의될 수 있다. 일 예로, 서브 6GHz이하 주파수인 FR1(Frequency Range 1)의 TDD(Time Division Duplex)에서

는 39936

또는 25600

일 수 있다. 39936

는 20.327μs이고, 25600

는 13.030μs이다. 또한, 밀리미터파(mmWave) 주파수인 FR2(Frequency Range 2)에서

는 13792

일 수 있다. 이때, 13792

는 7.020 μs이다.here,

may be a TA offset value that occurs due to duplex mode differences, etc. In FDD (Frequency Division Duplex)

has a value of 0, but in TDD (Time Division Duplex), considering the margin for DL-UL switching time,

It can be defined as a fixed value of . For example, in TDD (Time Division Duplex) of FR1 (Frequency Range 1), which is a frequency of sub-6 GHz,

is 39936

or 25600

It can be. 39936

is 20.327μs, 25600

is 13.030μs. Additionally, at FR2 (Frequency Range 2), which is the mmWave frequency,

is 13792

It can be. At this time, 13792

is 7.020 μs.

Figure 2 is a diagram showing an NR resource structure to which the present disclosure can be applied.

Resource Elements (REs) in the resource grid may be indexed according to each subcarrier spacing. Here, one resource grid can be created per antenna port and per subcarrier spacing. Uplink and downlink transmission and reception can be performed based on the corresponding resource grid.

는 하나의 RB 당 서브캐리어의 개수를 의미하고, k는 서브캐리어 인덱스를 의미한다.In the frequency domain, one resource block (RB) consists of 12 REs, and an index (nPRB) for one RB can be configured for each 12 REs. The index for RB can be utilized within a specific frequency band or system bandwidth. The index for RB can be defined as Equation 2 below. here,

means the number of subcarriers per RB, and k means the subcarrier index.

[Equation 2]

A variety of numerology can be set to meet the various services and requirements of the NR system. For example, an LTE/LTE-A system may support one subcarrier spacing (SCS), but an NR system may support multiple SCSs.

The new numerology for the NR system supporting multiple SCS is to solve the problem of not being able to use a wide bandwidth in the frequency range or carrier such as 700MHz or 2GHz, 3GHz or less, 3GHz-6GHz. , can operate in frequency ranges or carriers such as 6GHZ-52.6GHz or above 52.6GHz.

Table 1 below shows examples of numerology supported by the NR system.

[Table 1]

Referring to Table 1, the numerology can be defined based on the subcarrier spacing (SCS), Cyclic Prefix (CP) length, and number of OFDM symbols per slot used in the OFDM (Orthogonal Frequency Division Multiplexing) system. The above values can be provided to the terminal through upper layer parameters DL-BWP-mu and DL-BWP-cp for downlink, and through higher layer parameters UL-BWP-mu and UL-BWP-cp for uplink. .

In Table 1, when the subcarrier spacing setting index (u) is 2, the subcarrier spacing (Δf) is 60 kHz, and normal CP and extended CP can be applied. For other numerology indices, only normal CP can be applied.

A normal slot can be defined as a basic time unit used to transmit one piece of data and control information in the NR system. The length of the normal slot can be basically set to the number of 14 OFDM symbols. Additionally, unlike slots, subframes have an absolute time length equivalent to 1 ms in the NR system and can be used as a reference time for the length of other time sections. Here, for coexistence or backward compatibility between the LTE system and the NR system, a time interval such as a subframe of LTE may be required in the NR standard.

For example, in LTE, data may be transmitted based on a unit of time, Transmission Time Interval (TTI), and the TTI may be set in units of one or more subframes. Here, one subframe may be set to 1 ms and may include 14 OFDM symbols (or 12 OFDM symbols).

Additionally, non-slots may be defined in NR. A non-slot may mean a slot with a number that is at least one symbol smaller than a normal slot. For example, when providing low latency such as URLLC service, latency can be reduced through non-slots with a smaller number of symbols than normal slots. Here, the number of OFDM symbols included in the non-slot can be determined considering the frequency range. For example, in frequency ranges above 6 GHz, non-slots of 1 OFDM symbol length may be considered. As a further example, the number of OFDM symbols defining a non-slot may include at least two OFDM symbols. Here, the range of the number of OFDM symbols included in the non-slot can be set as the length of the mini slot up to a predetermined length (for example, normal slot length - 1). However, as a non-slot standard, the number of OFDM symbols may be limited to 2, 4, or 7 symbols, but is not limited thereto.

Additionally, for example, in the unlicensed band below 6 GHz, subcarrier spacing with u equal to 1 and 2 may be used, and in the unlicensed band above 6 GHz, subcarrier spacing with u equal to 3 and 4 may be used. For example, if u is 4, it may be used for SSB (Synchronization Signal Block).

[Table 2]

), 프레임 당 슬롯 개수(

), 서브프레임 당 슬롯의 개수(

)를 나타낸다. 표 2에서는 14개의 OFDM 심볼을 갖는 노멀 슬롯을 기준으로 상술한 값들을 나타낸다.Table 2 shows the number of OFDM symbols per slot for normal CP by subcarrier spacing setting (u) (

), number of slots per frame (

), number of slots per subframe (

). Table 2 shows the above-described values based on a normal slot with 14 OFDM symbols.

[Table 3]

Table 3 shows the number of slots per frame and slots per subframe based on a normal slot with 12 OFDM symbols per slot when the extended CP is applied (i.e., when u is 2 and subcarrier spacing is 60kHz). indicates the number of

As described above, one subframe may correspond to 1 ms on the time axis. Additionally, one slot may correspond to 14 symbols on the time axis. For example, one slot may correspond to 7 symbols on the time axis. Accordingly, the number of slots and symbols that can be considered for each within 10 ms corresponding to one wireless frame may be set differently. Table 4 can show the number of slots and symbols for each SCS. In Table 4, the SCS at 480 kHz may not be considered, but these examples are not limited.

[Table 4]

Additionally, as an example, in the existing wireless communication system, communication could be performed based on a terrestrial network consisting of terminals located on the ground and base stations located on the ground. The terminal can access the network via wireless. Here, when the terminal moves, the terminal can continuously receive the same service through other base stations in the terrestrial network. After connecting to the network, the terminal was able to access a specific service server through other wired or Internet networks. Additionally, the terminal was able to receive a service that connects wired or wireless communication with other terminals through the network.

However, the new wireless communication system can support terminal communication not only through terrestrial networks but also through non-terrestrial networks (NTN). Here, NTN may refer to a network or part of a network that uses a mobile object floating in the air or space equipped with a base station or relay equipment. As an example, NTN can support terminal-to-device communication services based on satellites equipped with communication functions in Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO). As another example, NTN can support terminal-to-device communication services based on aircraft equipped with communication functions within Unmanned Aircraft Systems (UAS), but is not limited to this.

In the following, terrestrial networks (TN) are distinguished from non-terrestrial networks (NTN). In other words, in the existing communication system, only the terrestrial network exists, so it could not be distinguished. On the other hand, in the following, NTN and TN are separately described as communication systems capable of communication between terminals based on NTN, and a method of supporting communication services between terminals is described based on this.

As an example, a wireless communication service between a terrestrial base station and a wireless terminal or a mobile base station is described as a mobile service, but is not limited thereto. Additionally, communication between mobile ground base stations and at least one space base station may be mobile satellite services. Additionally, wireless communication services between mobile ground base stations and space base stations or between mobile ground base stations via at least one space base station may also be mobile satellite services, but are not limited thereto.

The following describes a method of performing communication based on a wireless communication system that supports both mobile services and mobile satellite services. For example, NTN technologies have been introduced specifically for satellite communication, but NTN can also be introduced in TN's communication system (e.g. 5G system) to operate together with TN. Here, the terminal can support NTN and TN simultaneously. For a terminal that supports both NTN and TN, the wireless communication system may require specific technologies for NTN in addition to long-term evolution (LTE) and new radio (NR) systems, which are radio access technology (RAT). , the method for this is described below. As an example, the following may be definitions for each term related to NTN and TN.

Non-terrestrial networks (NTN):

A network or part of a network that uses a mobile device floating in the air or space equipped with a base station or relay equipment for communication

NTN-gateway:

A terrestrial base station or gateway located on the Earth's surface and equipped with sufficient radio access equipment to access satellites. Typically, an NTN gateway may be a transport network layer node (TNL).

Feeder link:

Wireless link between NTN gateway and satellite

Geostationary Earth orbit (GEO):

A circular orbit 35,786km above the Earth's equator, which coincides with the direction of Earth's rotation. The object or satellite in orbit orbits with the same period as the Earth's rotation period. Therefore, when observed from Earth, it appears to exist in a fixed location without movement.

Low Earth Orbit (LEO):

Orbit between 300km and 1500km above ground

Medium Earth Orbit (MEO):

Orbits exist between LEO and GEO

Unmanned Aircraft Systems (UAS):

Systems that typically operate 8km to 50km above ground may include High Altitude Platforms (HAPs). The unmanned aerial system may include at least one of the Tethered UAS (TUA), Lighter Than Air UAS (LTA), and Heavier Than Air UAS (HTA) systems.

Minimum Elevation angle:

Minimum angle required for a ground terminal to face a satellite or UAS base station in the air

Mobile Services:

Wireless communication service between a terrestrial base station and a wireless terminal or a mobile base station

Mobile Satellite Services:

It may be a wireless communication service between mobile ground base stations and one or more space base stations, between mobile land base stations and space base stations, or between mobile ground base stations via one or more space base stations.

Non-Geostationary Satellites:

Satellites in LEO and MEO orbits may orbit the Earth with a period of approximately 1.5 to 10 hours.

On Board processing:

Digital processing of uplink RF signals mounted on satellite or non-terrestrial equipment

Transparent payload:

This may mean changing the carrier frequency of the uplink RF signal and filtering and amplifying it before transmitting it through the downlink.

Regenerative payload:

Uplink RF signals are transformed and amplified before being transmitted through the downlink, and signal transformation may include digital processing such as decoding, demodulation, re-modulation, re-coding, and filtering.

On board NTN gNB:

It may refer to an onboard satellite in which a base station (gNB) is implemented in a regenerative payload structure.

On ground NTN gNB:

A terrestrial base station with a base station (gNB) implemented in a transparent payload structure

One-way latency:

In a wireless communication system, the time it takes to reach from a wireless terminal to a public data network or from a public data network to a wireless terminal.

Round Trip Delay (RTD):

It may be the time for any signal to travel from the wireless terminal to the NTN-Gateway or from the NTN-Gateway to the wireless terminal and then back again. At this time, the returning signal may be a signal containing a different form or message from the above arbitrary signal.

Satellite:

It may be a mobile vehicle in space equipped with a wireless communication transceiver capable of supporting transparent payload or regenerative payload, and may generally be located in LEO, MEO, or GEO orbit.

Satellite beam:

Beam generated by the onboard satellite antenna

Service link:

Wireless link between satellite and terminal (UE)

User Connectivity:

Ability to establish and maintain data/voice/video transmission between network and terminal

User Throughput:

Data transfer rate provided to the terminal

Figure 3 is a diagram showing an NTN including a transparent satellite to which the present disclosure can be applied.

Referring to FIG. 3, terminals included in the NTN may include terrestrial network terminals. As an example, NTN and TN terminals may include manned or unmanned moving vehicles such as ships, trains, buses, or airplanes, and may not be limited to a specific form. Referring to FIG. 3, a transparent satellite payload generated through a network including a transparent satellite may be implemented in a manner corresponding to an RF repeater.

More specifically, a network including transparent satellites can perform frequency conversion and amplification on wireless signals received in both uplink and downlink directions and transmit wireless signals. Therefore, the satellite can perform the function of relaying the NR-Uu wireless interface including both feeder link and service link directions, and the NR-Uu wireless interface will be described later.

As another example, referring to FIG. 3, a Satellite Radio Interface (SRI) on the feeder link may be included in the NR-Uu interface. That is, the satellite may not be the endpoint of the NR-Uu interface. Here, the NTN gateway can support all functions necessary to deliver signals defined in the NR-Uu interface. For example, other transparent satellites may be connected to the same base station on the ground. That is, a configuration in which multiple transparent satellites are connected to one terrestrial base station may be possible. The base station may be an eNB or gNB, but may not be limited to a specific type.

FIG. 4 is a diagram illustrating an NTN including a regenerative satellite without inter-satellite links (ISL) to which the present disclosure can be applied.

Referring to Figure 4, NTN may include a regenerative satellite. Here, a regenerative satellite may mean that a base station function is included within the satellite. As an example, a regenerative satellite payload generated through a network including regenerative satellites may be implemented by regenerating signals received from the ground.

More specifically, the regenerative satellite can receive signals from the ground based on the NR-Uu radio interface on the service link between the terminal and the satellite. As another example, a regenerative satellite can receive signals from the ground through SRI (Satellite Radio Interface) on a feeder link between NTN gateways. Here, SRI (Satellite Radio Interface) can be defined in the transport layer between the satellite and the NTN gateway. The transport layer may refer to the transport layer among the layers defined as OSI 7 layers. That is, a signal from the ground based on a reproduction satellite may be transformed based on digital processes such as decoding, demodulation, re-modulation, re-coding, and filtering, but is not limited thereto.

Figure 5 is a diagram showing an NTN including a reproduction satellite with an ISL to which the present disclosure can be applied.

Referring to FIG. 5, ISL may be defined at the transport layer. As another example, ISL may be defined as a wireless interface or a visible light interface, and is not limited to a specific embodiment. Here, the NTN gateway can support all functions of the transport protocol. Additionally, each renewable satellite can be a base station, and multiple renewable satellites can be connected to the same 5G core network on the ground.

FIG. 6 is a diagram illustrating a user plane (UP) protocol stack structure in an NTN including a transparent satellite to which the present disclosure can be applied. Additionally, FIG. 7 is a diagram illustrating a control plane (CP) protocol stack structure in an NTN including a transparent satellite to which the present disclosure can be applied.

The NR Uu interface may be an interface defined by protocols for wireless connection between a terminal and a base station in an NR system. At this time, the NR Uu interface may include a user plane defined by protocols for user data transmission, including NTN. Additionally, the NR Uu interface may include a control plane defined by protocols for transmitting signaling including radio resource control information, etc., including NTN. As an example, the Medium Access Control (MAC) layer includes Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP). ) and Radio Resource Control (RRC), and the protocol for each layer may be defined based on NR among the 3GPP RAN-related standards, but may not be limited thereto.

As an example, Figure 6 may be a UP protocol stack structure based on a transparent satellite. That is, in satellites and NTN gateways, only frequency conversion and amplification of wireless signals received transparently can be performed and transmitted. Additionally, Figure 7 may be a CP protocol stack structure based on a transparent satellite. In other words, only frequency conversion and amplification can be performed on transparently received wireless signals in satellites and NTN gateways.

Based on the above, a wireless communication system that supports terminal-to-device communication over NTN and TN can be considered. Here, as an example, NTN may have a larger roundtrip time (RTT) between the terminal and the base station than the existing TN. Therefore, from the UP perspective, the terminal needs to store data to be transmitted through each of the uplink and downlink in the buffer for a longer period of time due to the increase in RTT. In other words, the terminal needs to store more data in the buffer. Accordingly, the terminal may require a larger memory capacity than before, which will be described later.

Figure 8 is a diagram showing a timing advance calculation method to which the present disclosure can be applied. As described above, since satellites included in the NTN are located in the sky, the signal round-trip time (RTT) may be long. For example, in the case of LEO, it may be located at an altitude of 300 km to 1,200 km, and in the case of GEO, it may be located more than 36,000 km above the equator. Therefore, propagation delay in NTN can be significantly greater than in TN. On the other hand, because NTN is located in the sky, cell coverage can be greater than that of a terrestrial network.

In other words, since the RTT and cell coverage of NTN may be different from that of TN, there is a need to newly define a method for obtaining time synchronization for uplink transmission in NTN. As an example, Figure 8 may be a method for calculating TA values generated according to satellite payload type.

More specifically, FIG. 8(a) may be a method of calculating a TA value when the satellite payload type is a playback payload. Additionally, Figure 8(b) may be a method for calculating the TA value when the satellite payload type is a transparent payload.

Here, for initial access and continuous maintenance of timing advance (TA) values, a case where the terminal knows the satellite ephemeris and the location of the terminal may be considered. Here, satellite orbital power may mean the distance between each satellite and the receiver and the location information of each satellite. As an example, the terminal can acquire the TA value by itself and then apply it. (Option 1 hereinafter). As another example, the terminal may receive instructions for TA compensation and correction from the network (Option 2 hereinafter).

For example, referring to FIG. 8(a), when the satellite payload type is a playback payload, the satellite can directly serve as a base station. At this time, the terminal can calculate the TA value required for uplink transmission including PRACH (physical random access channel). The terminal can calculate the common TA value (Tcom) and the terminal-specific TA value (TUEx). As an example, the common TA value (Tcom) may be the TA value required for all terminals due to the large cell coverage and long round trip time (RTT) of the NTN. In other words, since the NTN is located in the sky and has a relatively longer distance than the distance between terminals, a common TA value (Tcom) that takes into account the long round trip time (RTT) in cell coverage may be necessary. Additionally, the TA value (TUEx) for each terminal may be a value generated due to the different positions of each terminal within cell coverage. If the terminal knows the location of the satellite at a specific time in advance through the satellite ephemeris stored in advance or received from NTN and knows the location of the terminal through a function such as GNSS, the terminal can detect the satellite at a specific time. Since the distance between the device and the corresponding terminal can be calculated, the TA value can be corrected after learning the TA value by oneself, and through this, the TA value can be determined.

Through the above, the terminal can perform uplink timing alignment between terminals received from the base station with full TA compensation.

As another example, the terminal may perform downlink and uplink frame timing alignment on the network side. As shown in Figure 8(b), when the satellite payload type is a transparent payload, the satellite can perform filtering and amplification of the wireless signal and transmit the signal to the NTN gateway. In other words, the satellite can operate like an RF repeater. At this time, a case may arise where the NTN gateway needs to be changed based on the continuous movement of the satellite. In FIG. 8(b), the common TA value (Tcom) can be determined based on the sum of the distance D01 between the reference point and the satellite and the distance D02 between the satellite and the NTN gateway. At this time, the feeder link may change as the NTN gateway changes based on the movement of the satellite. That is, the distance between the satellite and the NTN gateway may be changed based on the changed feeder link. Therefore, the common TA value may be changed, and there is a need for updating in the corresponding terminal. In addition, when setting an offset between downlink frame timing and uplink frame timing in the network, there is a need to additionally consider the case where the TA value occurring due to the feeder link is not corrected using the full TA compensation method. In addition, if the terminal can only calculate a different TA value (TUEx) for each terminal, the terminal needs to check one reference point for each beam or cell and transmit this information to other terminals. There is a need. When the network sets an offset between downlink frame timing and uplink frame timing, the network needs to manage offset information regardless of the satellite payload type. Here, as an example, the network may provide values for TA correction to each terminal, and is not limited to the above-described embodiment.

As another example, a method of instructing TA compensation and correction in the network (Option 2) may be considered. At this time, a common TA value can be generated based on common elements for propagation delay shared by all terminals located within the satellite beam or cell coverage. The network may transmit a common TA value to terminals for each beam or cell of each satellite based on a broadcast method. A common TA value can be calculated in the network assuming at least one reference position for each satellite's beam or cell. Additionally, the TA value (TUEx) for each terminal can be determined based on the random access procedure defined in the existing communication system (e.g. Release 15 or Release 16 of the existing NR system). At this time, for example, when applying a long TA value or a negative TA value, a new field may be needed in the random access message. For example, when the network provides a timing change rate to the terminal, the terminal can support TA value correction based on this.

FIG. 9 is a diagram illustrating an earth fixed cell scenario to which the present disclosure can be applied.

Referring to FIG. 9, a fixed cell may be a cell in which the location where signals are transmitted from the satellite is fixed. For example, because satellites move over time, antennas and beams must be varied to ensure service coverage is fixed at a specific location to maintain a fixed cell. At this time, as an example, in FIG. 9, satellite 1 (910) may maintain a fixed cell while varying the antenna and beam during T1 to T3. Here, when a specific time (T4) elapses, satellite 1 can no longer service the location, so satellite 2 (920) provides service at the location, thereby maintaining service continuity. At this time, after time T4, the beam or cell of Satellite 2 (920), which serves the same location as the location served by Satellite 1 (910) in the previous time (T1 to T3), is the beam or cell of Satellite 1 (910). The characteristics can be maintained and are not limited to the above-described embodiments.

As a more specific example, when a service is provided to Satellite 1 (910) and Satellite 2 (920), at least one of a physical cell ID (PCI) value and system information may remain the same. In other words, it is a cell with fixed service coverage and can generally be set based on satellites whose antenna and beam angles can be varied among satellites in LEO and MEO orbits excluding GEO.

On the other hand, FIG. 10 is a diagram illustrating an earth moving cell scenario to which the present disclosure can be applied. For example, a cell with moving service coverage may be an earth moving cell.

As an example, referring to FIG. 10, Satellite 1 (1010), Satellite 2 (1020), and Satellite 3 (1030) may each provide services through their respective cells with different PCIs. At this time, the antenna and beam through which the satellite transmits signals to the ground are fixed, and the form in which service coverage moves as the satellite moves with time can be referred to as an earth moving cell. The ground mobile cell can be set based on satellites with fixed antenna and beam angles among satellites in LEO and MEO orbits excluding GEO. Here, the satellites can have the advantage of being cheaper and having a lower failure rate than satellites that can adjust the angle of the antenna and beam.

Additionally, FIG. 11 is a diagram illustrating a method of mapping PCI to satellite beams to which the present disclosure can be applied.

As an example, PCI may refer to an index that can logically distinguish one cell. That is, beams with the same PCI value may be included in the same cell. As an example, referring to FIG. 11(a), PCI may be allocated to multiple satellite beams. On the other hand, referring to FIG. 11(b), one PCI may be allocated to each satellite beam in one satellite. As an example, a satellite beam may be composed of one or more SSB (Synchronization Signal Block, SS/PBCH block) beams. One cell (or PCI) can consist of up to L SSB beams. Here, L may be 4, 8, 64, or 256 depending on the size of the frequency band and/or subcarrier band, but is not limited to the above-described embodiment. That is, in L, one or several SSB indexes can be used for each PCI, similar to the terrestrial network (TN), which is an existing communication system (NR system). Through this, SSBs transmitted through different beams can be distinguished, and the SSB index can be mapped to a logically defined antenna port or a physically separated beam.

As an example, a terminal that can access the NTN may be a terminal that supports the GNSS (Global Navigation Satellite System) function. However, terminals that can access NTN may include terminals that do not support GNSS. As another example, NTN is a terminal that supports the GNSS function, but it can also support terminals that cannot secure location information through GNSS, and is not limited to the above-described embodiment.

As described above, the terminal can perform communication through NTN. As an example, the terminal may be provided with a 5G/B5G NTN-based non-terrestrial network-based service. Through this, the terminal can escape regional, environmental, spatial and economic constraints on wireless access services (e.g., LTE, NR, WiFi, etc.) based on installation of terrestrial network equipment. As an example, based on the above, advanced wireless access technology provided on a terrestrial network can be applied to non-terrestrial network platforms (e.g., satellites and UAVs). Through this, various wireless access service products and technologies can be provided along with advanced network technology.

The NTN platform can be operated as a kind of mirror by being equipped with a NR signal relay function or a base station (gNB, eNB) function in space or at high altitudes. For example, as already mentioned, the NG-RAN based NTN architecture may be implemented with the “Transparent payload-based NTN” and “Regenerative payload-based NTN” structures, which are as described above.

Additionally, as an example, NTN technology can be used for wider coverage and more wireless access services as an expanded network structure and technology of the 5G IAB (Integrate Access and Backhaul) architecture. Integration of NTN and terrestrial networks can ensure service continuity and scalability of 5G systems.

As a specific example, NTN and TN convergence networks can provide significant gains in terms of 5G target performance (e.g., user experience data rate and reliability) in urban and suburban areas. As another example, NTN and TN integrated networks can ensure connectivity not only in very dense areas (e.g., concert halls, sports stadiums, shopping centers, etc.), but also for fast-moving objects such as airplanes, high-speed trains, vehicles, and ships. there is. As another example, the NTN and TN integrated network can use data transmission services from the NTN network and the TN network simultaneously through the multi-connection function. At this time, depending on the characteristics of the traffic and the degree of traffic loading, both the efficiency and economic feasibility of the 5G wireless transmission service can be achieved by selectively utilizing a better network.

Terminals located on plain ground can use wireless data services by simultaneously connecting the NTN network and the TN network. In addition, the terminal can simultaneously connect to one or more NTN platforms (e.g., two or more LEO/GEO satellites) to provide wireless data access services for poor environments or areas that are difficult to support in the TN network. Through this, the terminal can be used in connection with various services. In particular, the integrated NTN network and TN network can improve the reliability of autonomous driving services and perform efficient network operation, and are not limited to the above-described embodiments.

Here, as an example, the limitations of services that can be provided by V2X technology based on LTE mobile communication or standard technology based on the IEEE 802.11p standard may be similar. The LTE V2X standard can be provided to meet the requirements defined in C-ITS (e.g., time delay of about 100ms, reliability of about 90%, and generation of messages of tens to hundreds of bytes in size about 10 times per second, etc.). Therefore, new V2X services that require low latency, high reliability, high volume data traffic, and improved location determination may be needed. At this time, as an example, standardization of 5G wireless access technology (e.g., NR (New Radio)) is in progress based on the above-described information. In addition, as an example, standardization of various numerology and frame structures and corresponding L2/L3 protocol structures is in progress to respond more flexibly to the requirements of new services than LTE. Based on the above, it may be possible to support improved V2X services such as autonomous driving or remote driving by introducing sidelink wireless access technology based on 5G mobile communication technology, and the NTN network can be utilized for this purpose.

As another example, the NTN network can be used to support IoT services in poor environments and areas not covered by terrestrial networks. For example, depending on the purpose of use, IoT devices may frequently need to perform wireless communication with minimal power consumption in poor channel environments (e.g. mountains, deserts, or the sea). Previously proposed cellular-based technologies may be primarily aimed at mobile broadband (MBB) services. Therefore, the efficiency of providing IoT services in terms of wireless resource utilization and power control may be low, and flexible operation may not be supported. Additionally, as an example, in the case of existing non-cellular IoT technology, there may be limitations in providing various IoT services due to limited mobility support and coverage. Considering the above, an NTN network can be applied, through which services can be improved.

In addition, as an example, if 5G mobile communication-based sidelink technology is applied through the NTN network, wide coverage and mobility can be provided to users through a more efficient wireless communication method than the current Bluetooth/WiFi-based wearable equipment. . Additionally, it can be differentiated from existing communication standards in applications that require high data transmission rates and mobility support using wearable equipment (e.g. wearable multimedia services).

As another example, the public safety communication network can be improved and disaster communication coverage expanded through the NTN network. For example, the high-reliability, low-latency technology of the 5G mobile communication system through the NTN network can provide public services such as disaster response. For example, mobile broadband services can be supported even in deserts or high mountainous areas by using mobile base stations such as drones that support 5G mobile communication. In other words, if the NTN network is applied to public services, it may be possible to expand disaster communication coverage by covering various regions.

The terminal can perform communication in an NTN environment. Considering that the terminal performs communication in an NTN environment, operations to improve coverage may be considered. As a specific example, a terminal with 5.5 dBi antenna gain and 3 dB polarization loss (per antenna) can communicate with a LEO satellite operating based on LOS (Line of Sight) in an NTN environment, and a parameter set for this is configured. It can be. For example, the physical random access channel (PRACH), through which the random access channel (RACH) preamble is transmitted, may operate differently from the existing one in consideration of the NTN environment. As another example, a downlink (DL) channel may be configured differently from the existing one in consideration of NTN coverage. As another example, a terminal with high power can be applied in an NTN environment. However, this is only one example and is not limited to this.

FIG. 12 is a diagram for explaining a random access procedure to which the present disclosure can be applied.

Figure 12(a) may be a contention based random access procedure, and Figure 12(b) may be a non-contention-free random access procedure. In step 1 of FIG. 4(a), the terminal may transmit a random access preamble (or Msg1) to the base station. The preamble can be randomly selected by the terminal from a set of preamble candidates indicated through information provided from the base station (e.g. system information block (SIB), or dedicated RRC message). In step 2, the base station may transmit a RAR (or Msg2) to the UE, and the RAR may include a timing advance command (TAC) and an uplink grant (UL grant). In step 3, the terminal can perform uplink transmission (or Msg3 transmission) scheduled by the uplink grant provided from the base station. In step 4, the base station may transmit a contention resolution message (or Msg4) to the terminal. Through the contention resolution message, the terminal can determine whether random access is successful. In addition, the terminal can transmit a hybrid automatic repeat and request (HARQ)-ACK message for Msg4 to the base station through a physical uplink control channel (PUCCH), and through this, it can be confirmed whether reception of Msg4 was successful.

As an example, contention-based random access may include a 4-step method and a 2-step method. The two-stage contention-based random access procedure may consist of a stage A in which the terminal transmits information corresponding to Msg1 and Msg3, and a stage B in which the base station transmits information corresponding to Msg4 and Msg2. For example, the random access procedure may be either a 4-step method or a 2-step method, and may not be limited to a specific form.

Referring to FIG. 12(b), the terminal can perform a non-contention based random access procedure. In step 0 of FIG. 12(b), the base station may allocate a random access preamble to the terminal. Unlike the operation in which the UE randomly selects a preamble from a preamble candidate set in the contention-based random access of FIG. 12(a), in the non-contention random access of FIG. 12(b), the UE selects the preamble designated by the base station in step 1. It can be transmitted to the base station. For example, when a UE in an RRC active state hands over from a serving cell to a target cell, the UE may receive a random access preamble to be transmitted to the target cell from the network. In step 2, the random access procedure can be completed by the base station transmitting the RAR to the terminal.

As an example, the random access procedure may be performed considering the NTN environment. Here, the HARQ-ACK for Msg4 described above can be transmitted from the terminal to the base station through PUCCH. Before receiving the designated PUCCH resource configuration, the UE can transmit HARQ-ACK for Msg4 to the base station through the PUCCH resource in Table 5 below, and the PUCCH resource in Table 5 below is SIB (system information block) 1. It can be indicated through .

[Table 5]

However, repeated PUCCH transmission may not be set for the PUCCH resources in Table 5 described above. That is, when the UE transmits the HARQ-ACK for Msg4 to the base station through the PUCCH resources of Table 5 described above, the UE may not perform repeated PUCCH transmission. In an NTN environment, it is necessary to perform repeated PUCCH transmission including HARQ-ACK for Msg4 considering the distance between the terminal and the satellite, and a configuration method for this may be needed.

As an example, the base station may set the number of PUCCH repetitions in an NTN environment and instruct the UE to do so. The base station can set the number of PUCCH repetitions by considering the distance between the terminal and the satellite and instruct this to the terminal. As a specific example, the base station may indicate the number of PUCCH repetitions to all NTN terminals through semi-static signaling. Here, information about the number of PUCCH repetitions may be included in system information. That is, the NTN base station can deliver system information including PUCCH repetition number information to all NTN terminals.

As another example, the base station may indicate the number of PUCCH repetitions to the terminal through a CSI request bit in the RAR grant field. As an example, Table 6 below may be a RAR grant field. In an existing wireless communication system, the CSI request bit in the RAR grant field below may be a reserved bit and may not be used. Therefore, the base station can indicate the number of PUCCH repetitions to the terminal using the CSI request bit below. As a more specific example, if the CSI request bit is the first value, the PUCCH repetition number may be 4, and if the CSI request bit is the second value, the PUCCH repetition number may be 1. As another example, if the CSI request bit is the first value, the PUCCH repetition number may be 4, and if the CSI request bit is the second value, the PUCCH repetition number may be 1. However, this is only an example for convenience of explanation and is not limited thereto.

[Table 6]

As another example, the UE may directly select the number of PUCCH repetitions. Specifically, the terminal may measure reference signal received power (RSRP) or reference signal received quality (RSRQ) based on the measurement operation, and determine the number of PUCCH repetitions based on the measurement. Here, as an example, PRACH transmission may be set to correspond to the number of PUCCH repetitions. Each PRACH may include a corresponding PUCCH repetition number, and the UE may select a PRACH format/resource corresponding to the determined PUCCH repetition number and transmit the preamble to the base station. The base station can recognize the number of PUCCH repetitions based on the received PRACH format/resources.

As another example, the number of PUCCH repetitions can be indicated to the base station through PUSCH transmission of Msg3. As a specific example, the number of repeated transmissions of the PUCCH including HARQ-ACK for the PDSCH of Msg4 may be related to the number of repeated transmissions of the PUSCH of Msg3. That is, the base station can recognize the number of repeated transmissions of the PUCCH including the HARQ-ACK for the PDSCH of Msg4 based on the number of repeated transmissions of the PUSCH of Msg3.

As another example, the base station may measure the signal noise ratio (SNR) for Msg3 PUSCH and determine the number of PUCCH repetitions based on this. Afterwards, the base station can schedule the number of PUCCH repetitions and instruct the terminal through downlink control information (DCI) for Msg4. As an example, DCI may include a field for the number of PUCCH repetitions. Here, any one of the bits reserved for DCI can be used to indicate the number of PUCCH repetitions. As a specific example, the number of PUCCH repetitions can be indicated through a specific DCI field in DCI format 1_0 scrambled with a temporary C-radio network temporary identifier (TC-RNTI). As an example, a reserved bit of the downlink assignment index (DAI) in the DCI field may indicate the number of PUCCH repetitions. As another example, transmission power control (TPC) or modulation coding scheme (MCS) for PUCCH may indicate the number of PUCCH repetitions, but this is only an example and may not be limited thereto. As another example, DCI includes a separate field indicating the number of PUCCH repetitions, through which the number of PUCCH repetitions can be indicated to the terminal.

As another example, an NTN terminal capable of operating in an NTN environment may indicate terminal capability information to the base station in a random access procedure. That is, the NTN terminal can indicate to the base station that it can operate as an NTN terminal in the random access procedure. As a specific example, the NTN terminal can use a new DRMS port to transmit Msg3 PUSCH, and through this, it can indicate to the base station that it is an NTN terminal. That is, when the base station receives Msg3 PUSCH based on the DMRS port described above, it can recognize that the terminal that transmitted the message is an NTN terminal. As an example, an NTN terminal may transmit Msg3 PUSCH using DMRS port 1, and an existing terminal may transmit Msg3 PUSCH using DMRS port 0. The base station can recognize the terminal type by checking the DMRS port of the received Msg3 PUSCH, and based on the above, can instruct the NTN terminal without changing the existing terminal settings, thereby maintaining backward compatibility. However, this is only an example for convenience of explanation and may not be limited thereto.

As another example, the NTN terminal may indicate to the base station that it is an NTN terminal through the code point of the LCID (logical channel ID) in the random access procedure. As an example, Table 7 below may be the code point of LCID. Referring to Table 7 below, code points 37 to 43 may be reserved values and unused values. The terminal may indicate to the base station that the terminal supports repeated PUCCH transmission for Msg 4 HARQ ACK to the NTN terminal through at least one of code points 37 to 43 of the LCID, and through this, the base station can determine whether the terminal is an existing terminal or an NTN terminal. It is possible to recognize whether it is a terminal or not.

[Table 7]

FIG. 13 is a diagram illustrating a method of indicating terminal capability information for PUCCH repetitive transmission to which the present disclosure can be applied. Referring to FIG. 13, UE capability information for PUCCH repetitive transmission may be supported by specific PRACH resources. As an example, the base station may transmit system information for the NTN terminal. The terminal may receive the corresponding system information, select a PRACH resource based on the system information, and transmit a random access preamble to the base station. Here, each PRACH resource may be associated with a different PUCCH repetition number. PRACH resources may consist of a RACH occasion (RO) and one of 64 preamble indexes, which may be as shown in FIG. 13. Here, each PRACH resource may be associated with each PUCCH repetition number. That is, the terminal can receive system information and transmit a random access preamble to the base station through the PRACH resource corresponding to the number of PUCCH repetitions.

As a specific example, referring to FIG. 13, SSB#2 (1310) configures PRACH resources in RO_msg4 (1320) with a new SSB-RO (RACH occasion) mapping for repeated PUCCH transmission including HARQ-ACK for Msg4. can do. After receiving SSB#2 (1310), the terminal can transmit a random access preamble through RO_msg4 (1320), through which the base station can recognize that the terminal performs PUCCH repeated transmission. The UE may perform a random access procedure and repeatedly transmit a PUCCH including a HARQ-ACK for Msg4 based on the set number of PUCCH repetition transmissions after receiving Msg4.

FIG. 14 is a diagram illustrating a method for indicating the number of PUCCH repeated transmissions to which the present disclosure can be applied. Referring to FIG. 14, terminal 1410 can receive SIB from base station 1420. Here, the SIB may include information indicating that the CSI request bit in the RAR grant indicates the number of PUCCH repetitions. That is, the terminal 1410 can recognize through the SIB that the number of PUCCH repetitions is indicated through the CSI request bit in the RAR grant. Afterwards, the terminal 1410 can transmit Msg1 and receive DCI and Msg2 including scheduling for Msg2 from the base station 1420. Here, the CSI request bit in the RAR grant of Msg2 may indicate the number of PUCCH repetitions. For example, if the CSI request bit is the first value, the PUCCH repetition number may be 4, and if the CSI request bit is the second value, the PUCCH repetition number may be 1, but this is only an example and is not limited thereto.

As another example, the number of PUCCH repetitions including HARQ-ACK for Msg4 may be indicated through PUSCH transmission of Msg3, as described above. Afterwards, the terminal 1410 may receive Msg4 from the base station 1420 and, in response, repeatedly transmit a PUCCH including HARQ-ACK based on the set number of PUCCH repetitions.

Figure 15 is a diagram showing a method of indicating NTN terminal capability information to which the present disclosure can be applied. Referring to FIG. 15, terminal 1510 can receive SIB from base station 1520. As an example, the SIB may indicate configuration for PUCCH repeated transmission including HARQ-ACK for Msg4, but is not limited to this.

The terminal 1510 can receive the SIB and transmit Msg1. Afterwards, the terminal 1510 may receive Msg2 and transmit Msg3 to the base station 1520. Here, as an example, Msg3 may indicate the configuration for PUCCH repeated transmission including HARQ-ACK for Msg4 as NTN terminal capability information, but is not limited to this.

Afterwards, the terminal 1510 may receive Msg4 from the base station 1420 and, in response, repeatedly transmit a PUCCH including HARQ-ACK based on the set number of PUCCH repetitions.

Figure 16 is a flowchart of a method for indicating the number of PUCCH repetitions to which the present disclosure can be applied. Referring to FIG. 16, the terminal can obtain system information from the base station (S1610). As an example, the system information may indicate the number of PUCCH repetitions, but may not be limited thereto. As another example, the system information may include information indicating that the CSI request bit in the RAR grant indicates the number of PUCCH repetitions. That is, the terminal can recognize through system information that the number of PUCCH repetitions is indicated through the CSI request bit in the RAR grant. Afterwards, the terminal may transmit Msg1 to the base station (S1620) and receive Msg2 from the base station (S1630). Here, as an example, the CSI request bit in the RAR grant of Msg2 may indicate the number of PUCCH repetitions. For example, if the CSI request bit is the first value, the PUCCH repetition number may be 4, and if the CSI request bit is the second value, the PUCCH repetition number may be 1, but this is only an example and is not limited thereto.

Afterwards, the terminal may transmit Msg3 to the base station. (S1640) Here, as an example, the number of PUCCH repetitions including HARQ-ACK for Msg4 may be indicated through PUSCH transmission of Msg3, as described above. . Afterwards, the terminal may receive Msg4 from the base station (S1650) and, in response, may repeatedly transmit PUCCH including HARQ-ACK based on the set number of PUCCH repetitions (S1660).

Figure 17 is a flowchart showing a method of indicating NTN terminal capability information to which the present disclosure can be applied. Referring to FIG. 17, the terminal can receive system information from the base station (S1710). As an example, the SIB may indicate the configuration for PUCCH repeated transmission including HARQ-ACK for Msg4, but is not limited to this. No.

After receiving the system information, the terminal may transmit Msg1 to the base station (S1720). After that, the terminal may receive Msg2 (S1730) and transmit Msg3 to the base station (S1740). Here, as an example, Msg3 is NTN terminal capability information may indicate configuration for PUCCH repeated transmission including HARQ-ACK for Msg4, but is not limited to this. Afterwards, the terminal may receive Msg4 from the base station (S1750) and, in response, repeatedly transmit PUCCH including HARQ-ACK based on the set number of PUCCH repetitions. (S1760)

Figure 18 is a diagram showing a device configuration to which the present disclosure can be applied.

Referring to FIG. 18, the first device 1800 and the second device 1850 can communicate with each other. At this time, as an example, the first device 1800 may be a base station device and the second device 1850 may be a terminal device. As another example, both the first device 1800 and the second device 1850 may be terminal devices. That is, the first device 1800 and the second device 1850 may be devices that communicate with each other based on NR-based communication.

As an example, a case where the first device 1800 is a base station device and the second device 1850 is a terminal device can be considered. At this time, the base station device 1800 may include a processor 1820, an antenna unit 1812, a transceiver 1814, and a memory 1816. The processor 1820 performs baseband-related signal processing and may include an upper layer processing unit 1830 and a physical layer processing unit 1840. The upper layer processing unit 1830 may process operations of a MAC (Medium Access Control) layer, RRC (Radio Resource Control) layer, or higher layers. The physical layer processing unit 1840 may process physical (PHY) layer operations (e.g., uplink reception signal processing, downlink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1820 may also control the overall operation of the base station device 1800. The antenna unit 1812 may include one or more physical antennas, and when it includes multiple antennas, it may support Multiple Input Multiple Output (MIMO) transmission and reception. Additionally, beamforming may be supported. The memory 1816 may store information processed by the processor 1820, software related to the operation of the base station device 1800, an operating system, and applications, and may also include components such as buffers. The processor 1820 of the base station device 1800 may be configured to implement the operations of the base station in the embodiments described in the present invention.

The terminal device 1850 may include a processor 1870, an antenna unit 1862, a transceiver 1864, and a memory 1866. As an example, in the present invention, the terminal device 1850 can communicate with the base station device 1800. As another example, in the present invention, the terminal device 1850 can perform sidelink communication with another terminal device. That is, the terminal device 1850 of the present invention refers to a device that can communicate with at least one of the base station device 1800 and other terminal devices, and is not limited to communication with a specific device. The processor 1870 performs baseband-related signal processing and may include an upper layer processing unit 1880 and a physical layer processing unit 1890. The upper layer processing unit 1880 can process operations of the MAC layer, RRC layer, or higher layers. The physical layer processing unit 1890 may process PHY layer operations (e.g., downlink received signal processing, uplink transmitted signal processing, and sidelink signal processing). In addition to performing baseband-related signal processing, the processor 1870 may also control the overall operation of the terminal device 1850. The antenna unit 1862 may include one or more physical antennas, and may support MIMO transmission and reception when it includes a plurality of antennas. Additionally, beamforming may be supported. The memory 1866 may store information processed by the processor 1870, software related to the operation of the terminal device 1850, an operating system, applications, etc., and may also include components such as buffers. The terminal device 1850 according to an example of the present invention may be associated with a vehicle. As an example, terminal device 1850 may be integrated into, located in, or on a vehicle. Additionally, the terminal device 1850 according to the present invention may be the vehicle itself. Additionally, the terminal device 1850 according to the present invention may be at least one of a wearable terminal, AV/VR, IoT terminal, robot terminal, and public safety terminal. The terminal device 1850 to which the present invention can be applied is any type of device that supports interactive services using side links for services such as Internet access, service performance, navigation, real-time information, autonomous driving, and safety and risk diagnosis. It may also include communication devices. In addition, AR/VR devices capable of sidelink operation or any type of communication device that becomes a sensor and performs a relay operation may be included.

Here, the vehicle/terminal to which the present invention is applied may include an autonomous vehicle/driving terminal, a semi-autonomous vehicle/driving terminal, a non-autonomous vehicle/driving terminal, etc. Meanwhile, the terminal device 1850 according to an example of the present invention is described as being associated with a vehicle, but one or more of the UEs may not be associated with the vehicle. This is an example and should not be construed to limit application of the present invention to the described example. Additionally, the terminal device 1850 according to an example of the present invention may also include various types of communication devices capable of performing cooperation to support interactive services using sidelinks. In other words, not only can the terminal device 1850 directly support an interactive service using a sidelink, but it can also be used as a cooperative device to support an interactive service using a sidelink.

The terminal device 1850 can obtain system information. As an example, system information may indicate the number of PUCCH repetitions, but may not be limited thereto. As another example, the system information may include information indicating that the CSI request bit in the RAR grant indicates the number of PUCCH repetitions. That is, the terminal device 1850 can recognize through system information that the number of PUCCH repetitions is indicated through the CSI request bit in the RAR grant. Afterwards, the terminal device 1850 may transmit Msg1 and receive Msg2. Here, as an example, the CSI request bit in the RAR grant of Msg2 may indicate the number of PUCCH repetitions. For example, if the CSI request bit is the first value, the PUCCH repetition number may be 4, and if the CSI request bit is the second value, the PUCCH repetition number may be 1, but this is only an example and is not limited thereto.

Afterwards, the terminal device 1850 may transmit Msg3. Here, as an example, the number of PUCCH repetitions including HARQ-ACK for Msg4 may be indicated through PUSCH transmission of Msg3, as described above. Afterwards, the terminal device 1850 may receive Msg4 and, in response, repeatedly transmit a PUCCH including HARQ-ACK based on the set number of PUCCH repetitions.

As another example, NTN terminal capability information may be indicated. The terminal device 1850 may receive system information, and the SIB may indicate configuration for PUCCH repeated transmission including HARQ-ACK for Msg4, but is not limited to this.

The terminal device 1850 may transmit Msg1 after receiving system information. Afterwards, the terminal device 1850 may receive Msg2 and transmit Msg3 to the base station. Here, as an example, Msg3 may indicate configuration for PUCCH repeated transmission including HARQ-ACK for Msg4 as NTN terminal capability information, but is not limited to this. Afterwards, the terminal device 1850 may receive Msg4 and, in response, repeatedly transmit a PUCCH including HARQ-ACK based on the set number of PUCCH repetitions.

Additionally, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. For hardware implementation, one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), general purpose It can be implemented by a processor (general processor), controller, microcontroller, microprocessor, etc.

The scope of the present disclosure is software or machine-executable instructions (e.g., operating system, application, firmware, program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or computer, and such software or It includes non-transitory computer-readable medium in which instructions, etc. are stored and can be executed on a device or computer.

The various embodiments of the present disclosure do not list all possible combinations but are intended to explain representative aspects of the present disclosure, and matters described in the various embodiments may be applied independently or in combination of two or more.

Base Station: 1800 Processor: 1820
Upper layer processing unit: 1830 Physical layer processing unit: 1840
Antenna unit: 1812 Transceiver: 1814
Memory: 1816 Terminal: 1850
Processor: 1870 Upper layer processor: 1880
Physical layer processing unit: 1890 Antenna unit: 1862
Transceiver: 1864 Memory: 1866

Claims (1)

In a terminal operation method in a wireless communication system,
A terminal receiving system information;
The terminal transmitting a random access preamble based on the system information;
Receiving a response to the random access preamble;
performing uplink transmission scheduled based on the uplink grant included in the response;
Receiving a contention resolution message based on the uplink transmission; and
A terminal operating method comprising repeatedly transmitting a physical uplink control channel (PUCCH) including a hybrid automatic repeat and request (HARQ)-ACK for the contention resolution message.